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Crash on invalid type parameter bound expression in conditional block #145187
Description
Crash report
What happened?
Found by the cpython3 fuzzer, see https://oss-fuzz.com/testcase-detail/5164455094976512.
>>> try:a
... finally:
... class h[l:{7for*()in 0}]:2
python: Python/compile.c:1163: _PyCompile_LeaveConditionalBlock: Assertion `c->u->u_in_conditional_block > 0' failed.
Aborted (core dumped)
I think I know how to fix it, I will open a PR.
CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux
Output from running 'python -VV' on the command line:
No response
Activity
gh-145187: Fix crash on invalid type parameter bound expression in co…
pythongh-145187: Fix crash on invalid type parameter bound expression…
gpshead commentedon Feb 24, 2026
i could reproduce it on debug builds of 3.14 but not 3.13 so I triggered the 3.14 backport. thanks for the fix!
[3.14] gh-145187: Fix crash on invalid type parameter bound expressio…
pythongh-145187: Fix crash on invalid type parameter bound expression…
pythongh-145187: Fix crash on invalid type parameter bound expression…